Balance Sheet Components - Marketable Securities (Details)	3 Months Ended
	Mar. 31, 2016 USD ($) security	Dec. 31, 2015 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 51,638,000
Unrealized Gains	2,000
Unrealized Losses	(51,000)
Fair Value	$ 51,589,000	$ 0
Securities in an unrealized loss position, greater than or equal to one year | security	0
Maximum maturity of marketable securities	2 years
U.S. government notes
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 9,089,000
Unrealized Gains	2,000
Unrealized Losses	0
Fair Value	9,091,000
Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	42,549,000
Unrealized Gains	0
Unrealized Losses	(51,000)
Fair Value	$ 42,498,000